Collapsible a-frame for road barriers

ABSTRACT

A collapsible A-frame ( 100 ) for use in a road barrier assembly ( 300 ) has an upper support means ( 152 ) adapted to support a barrier member ( 200 ) of the barrier assembly, and has first and second legs ( 110, 120 ) pivotally connected to a lower end of the upper support means. There is a cross member ( 130 ) pivotally connected to the first leg ( 110 ), and the second leg ( 120 ) can secure a free end ( 220 ) of the cross member ( 130 ) thereto by an interengagable male and female type joint assembly ( 210, 320 ). This occurs when the A-frame ( 100 ) assumes an expanded portion after the first and second legs ( 110, 120 ) have been pivoted apart and the cross member ( 130 ) has been pivoted away from the first leg ( 110 ).

TECHNICAL FIELD

The present invention relates to a collapsible A-frame for use in a road barrier assembly.

BACKGROUND ART

Known road barrier assemblies come in many different forms and sizes. A common form comprises a pair of A-frames that support a barrier member, typically an elongated beam. These A-frames have a fixed structure that, when stored after use, take up a large volume and so may increase transportation and storage costs. Their fixed structure also imposes burdens on workers who have to unload, convey and locate the A-frames on a work site.

DISCLOSURE OF INVENTION

It is an object of the present invention to overcome, or at least substantially ameliorate, the aforementioned disadvantages of the prior art.

According to one aspect of the invention there is provided a collapsible A-frame for use in a road barrier assembly, comprising an upper support means adapted to support a barrier member of the barrier assembly, first and second legs pivotally connected to a lower end of the upper support means, and a cross member pivotally connected to the first leg, the second leg including means for securing a free end of the cross member thereto when, in assuming an expanded position of the A-frame, the first and second legs have been pivoted apart and the cross member has been pivoted away from the first leg.

Preferably, the upper support means includes an aperture through which the barrier member can be located, the aperture being defined by at least two vertical support members separated by at least a bottom horizontal support member.

It is preferred that the free end of the cross member is, when the A-frame is in the expanded position, secured to the second leg by an interengagable male and female type joint assembly.

In a preferred form, the free end of the cross member has a groove which is engagable to a projection on the second leg, such that in use the application of downward force on the cross member causes the groove to engage the projection.

Preferably, the projection comprises a cross-sectional T shaped male portion connected to the second leg, and there is a stop portion at a lower end of the projection, the groove at the free end of the cross member comprising a cross-sectional T-shaped female portion so as to engage the male portion of the projection, such that in use the male portion of the projection is inserted into the female portion of the cross member and wherein the stop portion prevents further insertion.

It is preferred that the first and second legs are, when the A-frame is in a collapsed position, secured together by an interengagable ball and socket type joint assembly.

In a preferred form, the first leg has a socket means which is engagable to a ball means on the second leg when, in assuming the collapsed position of the A-frame, the cross member has been pivoted between the first and second legs and the first and second legs have been brought together.

Preferably, the ball means is located below the projection on the second leg.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a perspective view of a road barrier assembly incorporating a pair of collapsible A-frames according to a preferred embodiment of the invention.

FIG. 2 is a front view of a collapsible A-frame of the assembly shown in FIG. 1, when in a collapsed position.

FIG. 3 is a front view similar to FIG. 2 but showing the A-frame in a first stage of assuming an expanded position.

FIG. 4 is a front view similar to FIG. 3 but showing the A-frame in a second stage of assuming an expanded position.

FIG. 5 is a front view similar to FIG. 4 but showing the A-frame in a third stage of assuming an expanded position.

FIG. 6 is a front view similar to FIG. 5 but showing the A-frame in a final stage of assuming an expanded position.

FIG. 7 is a side view of the free end of the cross member of the A-frame shown in FIGS. 2 to 6.

FIG. 8 is a top view of the free end of the cross member shown in FIG. 7.

FIG. 9 is an end view of the free end of the cross member shown in FIGS. 7 and 8.

FIG. 10 is a side view of the projection on the second leg (shown in part) of the A-frame shown in FIGS. 2 to 6.

FIG. 11 is a top view of the projection on the second leg shown in FIG. 10.

FIG. 12 is an end view of the projection on the second leg shown in FIGS. 10 and 11.

FIG. 13 is a perspective view of a length of leg or cross member of a preferred A-frame of the invention.

MODES FOR CARRYING OUT THE INVENTION

FIG. 1 depicts two A-frames 100 assembled in conjunction with barrier 200 to form road barrier 300. Each A-frame 100 has been constructed so as to be lightweight, compact and collapsible. Each A-frame 100 possesses a first pivoting leg 110 and a second pivoting leg 120. The first pivoting leg 110 has attached to it a pivoting cross member 130 which pivots at point 135 and has a free end that is engaged by a projection 210 (shown in detail in FIGS. 10 to 12) and by a stop 150. Each set of legs 110, 120 also possess a ball and socket type joint assembly 140 for maintaining the legs in a collapsed position as depicted in FIG. 2. Each A-frame, In addition to first and second legs 110, 120, possesses an upper support means 152. The upper support means 152 has at its lower end two pivot points 115, 125 to which the legs 110, 120, respectively, are connected. Further, the upper support means comprises two vertical support members 155, 165 which are interconnected by upper and lower horizontal support members 175, 180 that together define an aperture 158, through which barrier member 200 is inserted and seated. In addition, certain other types of barriers and/or other instruments, such as warning lights, can be attached to the top of the A-frame through a hole 160.

FIGS. 2, 3, 4, 5, and 6 all show the same embodiment of the invention in its varying stages of assembly from a collapsed position to an expanded position. FIG. 2 depicts the A-frame in its most collapsed and secured form. In this form, the legs 110, 120 are held together through the joint assembly 140 which, in this particular embodiment of the invention, comprises a ball means and a socket means that, when interengaged, form a secure, yet reversible, connection. In other embodiments of the invention, horizontal support members 175, 180 can be shortened such that there is less gap between cross member 130 and second leg 120.

FIG. 3 depicts a first stage in assembling the A-frame for use. In this stage, legs 110, 120 have been opened to the desired angle. Indeed, pivot points 115, 125 can be constructed in such a way as to limit the range of pivoting possible such that the angles defined by the legs 110, 120 can be predetermined and fixed. Further, by setting the maximum range of pivoting to a certain angle, it is also possible to cause the feet 112, 122 of the legs to be levelled off so that they sit flat on the ground when both legs 110, 120 are extended outwards to the maximum degree as depicted in FIG. 3.

FIG. 4 depicts the cross member 130 being pivoted at point 135 in a downwardly direction. Again, the pivot point 135 can be made such that it ceases to pivot at a predetermined angle.

FIG. 5 depicts the almost finally assembled A-frame. In particular, it depicts the free end of cross member 130 in dose association with a cross sectional T shaped male portion of projection 210 and stop 150. With the downward application of force on cross member 130, the male portion of projection 210 becomes inserted into a cross sectional T shaped groove 320 (shown in detail in FIGS. 7 to 9) at the free end 220 of the cross member 130, and the free end becomes seated on stop 150.

Such a configuration, where the cross member 130 is seated on stop 150, is depicted in FIG. 6. In this configuration, the cross member is horizontal so as to increase the stability and strength of the A-frame.

FIGS. 7 to 12 depict various features of the free end 220 of the cross member 130 and of the T shaped projection 210.

As shown in FIG. 7, the free end 220 of cross member 130 is cut at an angle such that, when the cross member is horizontal, the split face 310 touching the second leg 120 is parallel with the leg 120, thus leaving little or no gap between cross member 130 and second leg 120. The T shaped groove 320 extends throughout the thickness of cross member 130 as depicted in FIGS. 8 and 9.

T shaped groove 320 is adapted to receive within it the T shaped projection 210 of the second leg 120. The T shaped projection 210 is connected to leg 120 along the base of the T, thereby forming the projection 210 as depicted in FIGS. 10, 11 and 12. Directly below the T shaped projection 210 is the stop 150. Stop 150 prevents the T shaped projection 210 from passing completely through the T shaped groove 320. It thereby causes the engaged cross member and leg assembly to be static at stop 150.

In order that the A-frame be easy to handle, it is preferable to include means for keeping the legs 110, 120 and cross member 130 together whilst the A-frame is in its collapsed state. For that purpose, a joint assembly 140 is utilised. The joint assembly 140 is shown separated in FIG. 1 and is shown engaged in FIG. 2. In the present embodiment, the joint assembly comprises a ball means and a socket means which engage each other with sufficient force to hold the legs and cross member together such that they can be handled as if they were a long, thin article.

The present embodiment described herein utilises injection moulded plastic pieces for assembly into the collapsible A-frame. Further, rather than utilise solid lengths of injection moulded plastic, the lengths of plastic feature a zig-zag backbone 330 with panelling 340, 350 on opposite sides as depicted in FIG. 13. This results in extremely lightweight yet strong lengths of plastic pieces.

Numerous modifications and alterations may be devised by those skilled in the art without departing from the spirit and scope of the present invention. Thus while the present invention has been shown in the drawings and described above with particularity and detail, it will be apparent to those of ordinary skill in the art that numerous modifications, including but not limited to, size, materials, shape, form, function and manner of operation, assembly and use, may be made without departing from the scope or ambit of the invention. 

1. A collapsible A-frame for use in a road barrier assembly, comprising an upper support means adapted to support a barrier member of the barrier assembly, first and second legs pivotally connected to a lower end of the upper support means, and a cross member pivotally connected to the first leg, the second leg including means for securing a free end of the cross member thereto when, in assuming an expanded position of the A-frame, the first and second legs have been pivoted apart and the cross member has been pivoted away from the first leg.
 2. The collapsible A-frame of claim 1 wherein the upper support means includes an aperture through which the barrier member can be located, the aperture being defined by at least two vertical support members separated by at least a bottom horizontal support member.
 3. The collapsible A-frame of claim 1 wherein the free end of the cross member Is, when the A-frame is in the expanded position, secured to the second leg by an interengagable male and female type joint assembly.
 4. The collapsible A-frame of claim 3 wherein the free end of the cross member has a groove which is engagable to a projection on the second leg, such that in use the application of downward force on the cross member causes the groove to engage the projection.
 5. The collapsible A-frame of claim 4 wherein the projection comprises a cross-sectional T shaped male portion connected to the second leg, and there is a stop portion at a lower end of the projection, the groove at the free end of the cross member comprising a cross-sectional T-shaped female portion so as to engage the male portion of the projection, such that in use the male portion of the projection is inserted into the female portion of the cross member and wherein the stop portion prevents further insertion.
 6. The collapsible A-frame of claim 1 wherein the first and second legs are, when the A-frame is in a collapsed position, secured together by an interengagable ball and socket type joint assembly.
 7. The collapsible A-frame of claim 6 wherein the first leg has a socket means which is engagable to a ball means on the second leg when, in assuming the collapsed position of the A-frame, the cross member has been pivoted between the first and second legs and the first and second legs have been brought together.
 8. The collapsible A-frame of claim 7 wherein the ball means is located below the projection on the second leg. 